This invention relates to monitoring and data gathering apparatus, and more particularly in one specific embodiment to traffic usage data gathering apparatus.
The gathering of data pertaining to the usage or traffic density of certain services and equipment is of considerable interest in a number of fields. In the telephone industry, for example, studies are conducted regularly to accumulate such data with regard to telephone equipment utilization. Interpretation of the accumulated data facilitates the proper assignment and disposition of the various telephone lines and equipment, determines the quantities of equipment necessary to handle given volumes of telephone traffic, and provides for further planning with regard to telephone equipment requirements. Thus, sufficiency of present units of equipment may be determined, units may be reallocated to areas of greater need, additional units may be allotted and the number of circuits between central offices may be altered, or other appropriate action taken, to provide optimal service consistent with overall economy of operation.
Usage data may be obtained, for example, by repeatedly scanning the various units of equipment at regular intervals and registering indications of whether the individual units of equipment are seized or are in use at the time of the scan. By assuming that a seizure or busy condition which is present at the time of the scan exists for the interval between successive scans, each indication registered is indicative of a precise period of usage of the individual unit being observed. Proper selection of the scanning interval provides the usage data in desired units of traffic measurement. For example, an effective scanning or data gathering rate of 36 scans per hour produces usage data in terms of hundred call seconds (CCS).
For the usage data to be of greatest practical use, it is desirable to gather the data in a form suitable for processing automatically by centralized data processing equipment. Typical arrangements widely used for gathering usage data in the telephone industry employ rotary or crossbar electromechanical apparatus, such as disclosed in Lamneck-Wichmann, U.S. Pat. No. 3,115,549, issued Dec. 24, 1963. Although generally satisfactory for usage data collection limited to periods of several hours daily, disadvantages have arisen related to wear and maintenance of such arrangements when used for greatly extended or nearly continuous data gathering, such as for real time or near-real time equipment monitoring. On the other hand, when such electromechanical arrangements are used for brief intervals (e.g., 5-10 minutes) for gathering data from equipment having short holding times, significant data errors may be introduced.
Another disadvantage of existing data gathering arrangements is that they typically permit grouping of the data gathering inputs only in fixed group sizes or in multiples of a certain group size. Moreover, such input grouping has been effected heretofore via wired crossconnection schemes, making grouping and subsequent regrouping of the data gathering points costly, time-consuming and error-prone tasks. In addition, such wired cross-connection schemes do not practically permit the occasional collection of ungrouped data from the individual gathering inputs, as may be desirable for maintenance and other purposes.
Further limitations encountered with existing arrangements relate to the number of data inputs that can be handled economically and to the ease and flexibility with which new data gathering features can be provided.
Accordingly, a need exists for improved data gathering apparatus which will economically and accurately gather data at variable scanning rates from large numbers of data gathering inputs and which will provide for flexible grouping and regrouping of the data gathering inputs with greater ease than known arrangements.